Automatic control mechanism



Feb. 4, 1936. K WA NE 2,029,349

AUTOMATIC CONTROL MECHANI SM Filed Feb. 23, 1932 Patented Feb. 4, 1936UNITED STATES PATENT OFFICE signor, by

mesne assignments, to

Magnesium Development Corporation, Newark, N. J a corporation ofDelaware Application February 2 In G 5 Claims.

The present invention relates to an electricallyoperated automaticcontrol mechanism, particularly for use in connection withautomaticallycontrolled die-casting apparatus.

In automatically-controlled mechanisms it is frequently desired tointerrupt the operation of the entire device for a definite intervalduring each working cycle, and it is an object of the present inventionto provide a control mechanism which will cause such an interruption tobe performed automatically for a period which is independent of theduration of the working cycle proper and which may be adjusted to suitvarious operating conditions.

The invention will be described hereinafter with reference to itsapplication in connection with die-casting apparatus. It will be seen,however, that it is by no means limited to such ap plication, but may beapplied equally well, with changes obviously occurring to the skilledtechnician, in all instances in which the aforementioned object is to beattained.

In the production of castings in die-casting apparatus it is oftennecessary to vary the solidification period, that is to say, theinterval of inaction between the termination of the moldcharging stepand the step of opening the mold sections, since this period varies withcastings of varying dimensions and shape. At the same time, it is founddesirable, especially in automaticallyoperated die-casting apparatus, toalso insure the maintenance of this interruption in the working cycle,or'period of rest, by mechanical .means, and further to be able toconveniently regulate the duration of the period of rest to suit thespecial features and characteristics of the various castings.

According to the present invention this problem is solved byincorporating in the control mechanism of the die-casting apparatus anadjustable, but otherwise automatic, electrically-actuated clutch, bymeans of which the drive of the machine is interrupted for an adjustableperiod of time. This is suitably effected by providing anelectrically-operated clutch, coupling the drive shaft of theapparatuswith the main control or operating shaft, and means for shutting off thecurrent supply to said clutch, and simultaneously, in a shunt circuit,setting a contact member in time-controlled motion, which restores thesupply of the current for operating the clutch at the end of anadjustable interval.

In order to more clearly understand the nature of this invention,reference is made to the accompanying drawing which diagrammatically 3,1932, Serial N... 594,759

ermany February 25, 1931 illustrates, by way of example, a typicalembodiment of the mechanism according to the principles of thisinvention, and in which:

Fig. 1 represents a view in front elevation of a mechanism embodying theprinciples of the invention;

Fig. 2 represents a view of the mechanism in side elevation, as viewedfrom the right of Fig. 1, portions of the apparatus being broken awayand shown in section to more clearly show its mode of construction;

Fig. 3 represents a cross sectional view taken along the line III-III ofFig. 1,

Referring to the drawing, 41 represents a graduated dial in cooperativerelationship with respect to a pointer b secured to the control shaft hof a die-casting machine or the like. As is well known to those versedin the art, the shaft h is adapted to control the various operations ofan automatic mechanism during its working cycle, and in accordance withthe invention the position of the pointer 12 secured to the shaft h. androtating therewith, is indicative at all times of the state of themachine with reference to a complete working cycle. In the drawingpointer b is shown in its position during the idling period of themachine.

Anelectromagnetically-operated clutch g is provided for coupling thecontrol shaft h with a main drive shaft 11, the shaft h beingconstructed in two sections connected together by means of a suitablecoupling '2 and electrically insulated from each other by means of asuitable interposed plate of fiber (not shown) within the coupling i. Anelectrical contact k is mounted upon the shaft h, the purpose of whichwill be hereinafter understood.

The pointer b is provided with two sliding contact members In and be bymeans of which electrical connection may be established between acontact ring c or a clock mechanism 12 and the main supply leads L1 andL2, the pointer b being constructed from conducting material and incircuit with the lead L1 through the medium of the contact ring itmounted on shaft h. Another lever e is rotatably mounted on the shaft hand is in electrical contact therewith. This lever is provided with acontact member c1 and an abutment or stop e2, said lever being adaptedto be moved either by the pointer I) through its engagement with theabutment e2 or by means of the electrical clock mechanism 11 which isset in motion at a moderate rate of speed in accordance with the desiredinterruption of the control shaft h during a working cycle. The clockdium of the ried forward with mechanism 11 is connected to the hub oflever e by means of a suitable gear transmission, 1, m. It will thus beseen that the lever e may be rotated with the pointer b and shaft h ormay be separately rotated with respect to said shaft h by means of theclock mechanism (1.

The pivotal axis of the lever e is in continuous electrical connectionwith the pointer b, whereas the sliding contact member e1 on the underside of this lever establishes electrical connection with a control oradjustable lever ,f, the control lever being rotatably mounted on theshaft h and insulated therefrom as by means of a fiber bushing r or thelike. The lever f is adjustable with respect to the contact ring c withwhich it is always in electrical connection through the meslidingcontact member f2, the ring 0 being discontinuous in that it is providedwith a gap 01.

In the operation of the control mechanism the contact ring 0 is adjustedon the dial a in such a manner that the sliding contact hi on the underside of the pointer b reaches the gap 01 in the contact ringc at themoment the die-casting process has proceeded to such an extent that theopening of the mold would follow as the next active operation in aworking cycle. At this moment the electrical circuit, including thepointer b, ring 0, clutch g and leads L1 and L2 is broken and thecurrent interrupted thereby, which action results in the disengagementof the electromagnetic clutch 9. That is, the control shaft h isdisconnected from the operating shaft p. At the same time, however, theelectrical circuit of the clock mechanism d is completed through themedium of the contact member 122 on the under side of pointer b comingin contact with the stationary contact member 173. The completion ofthis circuit sets the clock mecha-' nism din motion so that the lever emoves away from the pointer 17 and continues its course towards theright as viewed in Fig. 1. The period that elapses until. the contact e1of this lever reaches the contact member f1 onthe control lever f may bevaried at convenience by suitably adjusting the position of the lever,f, and the resulting establishment of an electrical connection betweene1 and f1 energizes the magnetic clutch 9 through the completion of theelectrical circuit with the ring 0 at f2, thereby rotating theshaft h,which enables the-machine to resume its working cycle, the firstfunction of which opens the mold. Rotation of the shaft h in performinga new working cycle moves the contact member In, of the pointer 21, intoelectrical connection with the contact ring 0 and at the same timebreaks the electrical connection b2 be, which latter action stops theclock mechanism d, temporarily arresting the forward movement of thelever e. As the shaft h and pointer b continue to rotate, the pointer bengages the abutment es With the result that the aforementioned lever isagain carthe pointer into the position shown in Fig. 1, at which pointthe gap 01 has been reached and the operation of shaft h is againinterrupted.

v It will be understood from the previous discussion of the operation ofthe mechanism constituting this invention that during the rotation ofthe pointer 22 through the medium of shaft h, and

' during the interval of driving Contact of lever e by pointer b theclock mechanism 11 will be actuated or mechanically driven.-Interruption in the rotation of-pcinter b, on places the pointer in theother hand (Fig. 1), position tocomplete the electrical drive for theclock mechanism d, which arrangement electrically actuates the clockmechanism to drive the lever e independent of the rotation of shaft h.

It is to be understood that the electromagnetic clutch above describedand the mechanism for controlling the same is not'restricted in itsapplication to die-casting apparatus, and may be employed in all casesin which, during a number of periodically recurring operations, a pauseof definite duration-which is adjusted according to circumstanceshas tobe interposed.

I claim:

1. An automatic control mechanism comprising driving means, mainoperating means, a clutch adapted to couple said driving means with saidmain operating means, means for electrically actuating said clutch,means for shutting off the current supply to said clutch-actuating meanswhen a predetermined position of said main operating means has beenattained, a contact member adapted to perform a movement ofpredetermined speed and duration, electrically actuated means adapted tocause such movement, means for restoring the current supply foractuating the said clutch at the termination of the movement of saidcontact member, and means adapted to establish the current supply tosaid movement-causing means incidentally with the shutting off of thecurrent supply to said clutchactuating means, said last-mentionedcurrentestablishing means being adapted to shut oif the current supplyto said movement-causing means incidentally with the restoration of thecurrent supply to said clutch-actuating means,

2. An automatic control mechanism comprising driving means, mainoperating means, a clutch adapted to couple said driving means with saidmain operating means, an electric circuit including a contact ring forelectrically actuating said clutch, means in the form of a gap in thecircumference'of said contact ring for shutting off the current supplyto said clutch-actuating means when a predetermined position of the mainoperating means has been attained, a contact member adapted to perform amovement of predetermined speed and duration, an electrically actuatedmeans adapted to cause such movement, means for restoring the currentsupply for actuating the said clutch at the termination of the movementof said contact member, and means adapted to establish the currentsupply to said movement-causing means incidentally with the shutting offof the current supply to said clutchactuating means, said last-mentionedcurrentestablishing means being adapted to shut ofi the current supplyto said movement-causing means incidentally with the restoration of thecurrent supply to said clutch-actuating means.

3. An automatic control mechanism comprising driving means, mainoperating means, a clutch adapted to couple said driving means with saidmain operating means, an electric circuit including a contact ring forelectrically actuating said clutch, means in the form of a gap in thecircumference of said contact ring for shutting oh the current supply tosaid clutch-actuating means when a predetermined position cf the mainoperating means has been attained, a contact member adapted to perform amovement of predetermined speed and duration, an electrically-operatedclock mechanism for driving said 4. An automatic control mechanismcomprising a driving shaft, a main operating shaft, a clutch adapted tocouple said driving and main operating shafts, a pointer secured to saidmain operating shaft and rotated thereby, a contact ring, said pointerhaving a contact member in sliding contact with said contact ring, anelec-v trical circuit for actuating said clutch, said electrical circuitincluding the pointer and contact ring, means in the form of a gap inthe circumference of said contact ring for interrupting said electricalcircuit to disengage said clutch and stop said main operating shaft, astationary contact member adjacent the gap in said contact ring, a leverarm mounted upon said main operating shaft and rotatably movable withrespect thereto, an electrically-actuated clock mechanism for drivingsaid lever arm, a shunt electric circuit including said pointer, saidstationary contact member and said clock mechanism for actuating theclock mechanism, said pointer, when opposite the gap in said contactring, being in electrical circuit with said stationary contact memberand closing said shunt circuit, an adjustable member in electricalconnection with said contact ring, a contact member disposed on saidlever arm and adapted to make contact with said adjustable member, saidcontact between the lever arm contact member and adjustable memberoccurring at a predetermined interval following the interruption in saidclutch-actuating electrical circuit, and said contact between the leverarm contact member and the adjustable member being adapted to restorethe electrical circuit to said clutch-actuating means.

5. An automatic control mechanism comprising an electromagnetic clutchinterposed a driving shaft and a control shaft, a stationary electricalconducting contact ring, an electrical conducting pointer secured tosaid control shaft and adapted to contact with said contact ring, anelectrical circuit including said contact ring and pointer forenergizing said clutch to normally maintain it engaged, a switch in theform of a gap in said contact ring for interrupting contact with saidpointer to thereby open the clutch electrical circuit, means formaintaining said clutch electrical circuit open a definite predeterminedinterval, said means comprising a shunt electrical circuit including thepointer and a contact member, means for closing said shunt circuit oninterrupted contact of the pointer and contact ring, a clock mechanismfor driving said contact member, said clock mechanism being actuatedelectrically through the medium of said shunt circuit, and an adjustablemember in electrical connection with said contact ring, said adjustablemember being adapted to be contacted by said contact member, wherebysaid clock mechanism is deenergized and said clutch electrical circuitclosed.

KARL FRIEDRICH WAGNER.

